In light-emitting devices in which a plurality of LED chips is mounted on a chip mount surface of a substrate provided with a wiring pattern, the larger the number of LED chips and the number of parallel connections of mounted circuits are, the more elaborately the wiring pattern need be designed in order that electric connection between the LED chips and the wiring pattern is provided.
A light-emitting device 91 of a conventional example shown in FIG. 4 is a Chip on Board (COB) light-emitting module, and includes a substrate 92, a positive electrode pattern 94 and a negative electrode pattern 95 as a wiring pattern 93, a chip mount surface 96, a plurality of LED chips 97 mounted on the chip mount surface 96, a frame 98 surrounding the chip mount surface 96, a sealant (not shown) filling the inside of the frame 98 to seal the LED chips 97, and a positive electrode 100 and a negative electrode 101 as electrodes located outside the frame 98.
In the illustrated example, 16 LED chips 97 are mounted, every two of which are connected in series, and there are eight parallel connections. In this case, if the wiring pattern 93 is merely provided along the periphery of the chip mount surface 96, it is difficult to provide electric connection because long bonding wires 103 are required etc. Accordingly, the wiring pattern 93 need be extended to the inner part of the chip mount surface 96. As an example, an extended portion 94a of the positive electrode pattern 94 and an extended portion 95a of the negative electrode pattern 95 may be arranged side by side in the central area of the chip mount surface 96, so that the chip mount surface 96 is divided into two areas, namely right and left areas 96a, 96b, by the extended portions 94a, 95a, and the LED chips 97 are mounted in each area 96a, 96b to provide the electric connection.